The Alexandra Magnolia (Magnolia x soulangiana ‘Alexandrina’) is a popular ornamental tree, valued for its spectacular spring blooms and elegant form. Its visual appeal makes it a popular choice for adding a refined touch to diverse landscapes. Its stunning floral display transforms the garden as winter transitions into spring, enhancing any outdoor space.
Understanding Alexandra Magnolia
The Alexandra Magnolia (Magnolia x soulangiana ‘Alexandrina’) is a deciduous hybrid tree. It typically reaches a mature height of 15 to 25 feet and spreads 10 to 20 feet. This tree exhibits an upright growth habit when young, gradually becoming more oval or rounded with age. Its glossy green leaves provide a lush backdrop through summer, eventually turning a golden yellow in the fall before dropping.
The most striking feature of the Alexandra Magnolia is its early spring bloom, with flowers often appearing before the leaves emerge. These showy, goblet or tulip-shaped flowers are large, typically measuring 3 to 6 inches across. They display a beautiful two-tone coloration, with deep pink or purplish-pink petals on the outside and paler, often creamy white, interiors. The flowers are lightly fragrant and may occasionally rebloom in midsummer.
Planting Alexandra Magnolia
Selecting the appropriate planting site is important for the Alexandra Magnolia’s long-term health. This tree thrives in full sun to partial shade, requiring at least 4 to 6 hours of direct sunlight daily for optimal flowering. It benefits from a sheltered location, protected from strong winds and harsh frosts, which can damage its early blooms. Avoid planting where pavement is salted in winter, as this can negatively affect the tree.
The Alexandra Magnolia prefers rich, well-drained, slightly acidic soil with a pH between 5.5 and 6.5. Heavy, waterlogged soils should be avoided, as good drainage is important to prevent root issues. To prepare the soil, dig a hole that is at least double the width of the root ball and as deep. Gently loosen the roots of the plant before placing it in the hole, ensuring the top of the root ball is level with the surrounding ground. Backfill the hole with native soil, gently tamping it down to remove air pockets, then water thoroughly to settle the soil.
Ongoing Care for Alexandra Magnolia
Consistent moisture is important for newly planted Alexandra Magnolias, requiring regular watering during the first growing season to establish a deep, extensive root system. Once established, the tree is moderately drought-tolerant but benefits from deep watering once a week, especially during dry periods. Allow the soil to dry slightly between watering sessions.
Fertilization supports healthy growth and abundant blooms for established Alexandra Magnolias. Apply a slow-release, balanced fertilizer, such as an 8-8-8 or 10-10-10 NPK ratio, in early spring before new growth begins. For younger trees, a higher nitrogen mix like 20-20-20 can be beneficial. Spread the fertilizer around the drip line of the tree, about 6-10 inches out from the trunk, to ensure the wide-spreading roots receive nutrients. Avoid fertilizing during the first year after planting to allow roots to establish.
Pruning requirements for Alexandra Magnolia are minimal, primarily focused on maintaining shape and health. The best time to prune deciduous magnolias like ‘Alexandrina’ is in late winter or early spring, or immediately after flowering. Remove any dead, diseased, or crossing branches to improve air circulation and light penetration within the canopy. While young trees can be pruned to shape, mature magnolias generally do not require extensive pruning, as they set buds on the previous year’s growth.
Addressing Common Challenges
Alexandra Magnolias are generally low-maintenance, but they can encounter certain issues. Environmental stresses, such as a late frost after buds have formed, can damage the early spring flowers. Mulching around the base of the tree in colder zones can help protect the roots during winter. Drought stress can lead to wilting, so consistent watering during dry spells is important.
Pest infestations are typically not severe, but occasional monitoring for scale insects and aphids is recommended. Scale insects can weaken branches and stunt growth, while aphids may cause discolored leaves. Powdery mildew is a common fungal disease that can affect leaves, though rarely requires chemical controls; removing infected leaves can help. Proper watering, adequate air circulation, and maintaining overall plant health can help mitigate most common challenges.